Method and apparatus for network device detection

ABSTRACT

A method and apparatus for detecting remote network devices. In one embodiment, the method comprises detecting an event and a) transmitting a message requesting a response from one or more remote network devices, the message comprising a first network identification code, and b) determining whether a response to the message has been received, the response transmitted by a remote network device after receiving the message and determining that the first network identification code matches a second network identification code stored within the remote network device, the response comprising identification information of the remote network device. If c) a response has not been received, terminating the method for detecting remote network devices if a pre-determined time period has elapsed since transmitting the message. If d) a response has been received, storing identification information associated with the responding remote network device and repeating steps a-d until no further responses are received.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/273,092, filed on Oct. 13, 2011, which is a continuation-in-part ofU.S. patent application Ser. No. 13/214,116, filed on Aug. 19, 2011, nowU.S. Pat. No. 8,619,819.

BACKGROUND Field of Use

The present application relates to the field of remote management andcontrol of electric or electro-mechanical devices. More specifically,the present application relates to a method and apparatus for networkdevice detection in home networks.

Description of the Related Art

Network technology has proliferated over the years, thanks to theubiquitous nature of the Internet. Millions of home and businessnetworks have been set up to access network resources, such as printers,computers, and other peripheral devices on the network. Such networkstypically rely on a router and one or more remote network devices eachpossessing the necessary hardware, software, and/or firmware to enablecommunications to the router.

The most familiar type of routers are home and small office routers thatsimply pass data, such as web pages and email, between the homecomputers and the owner's cable or DSL modem, which connects to theInternet (ISP). However more sophisticated routers range from enterpriserouters, which connect large business or ISP networks up to the powerfulcore routers that forward data at high speed along the optical fiberlines of the Internet backbone.

When a new network is set up, a router is generally installed first.They are typically programmed during the manufacturing process toinclude a pre-assigned IP address, the most commonly one used todaybeing 192.168.1.1. Wireless routers are additionally pre-programmed witha service-set identifier (SSID) that uniquely identifies the router and,thus, a particular local-area network (LAN). Users must generally changethe default SSID to avoid interference with other wireless routers thatmay be operating nearby.

After a router has been set up, peripheral devices may then be connectedto it. In the case of a wireless network, peripheral devices mustgenerally detect the SSID and often be supplied with a password if datasignals from the router are encrypted. Users of the network mustgenerally have some knowledge of how to connect their peripheral deviceswirelessly to the router.

In some networks, hardware may not take the form of the typical routerand peripheral devices. This may be the case, for example, with customautomated outdoor home lighting systems. In this case, the router maytake the form of a central control device and peripheral devices maytake the form of a slave controller device that is able to communicatewirelessly with the central control device. In these custom networks,traditional ways of slave setup may be non-existent. However, it isstill imperative that the central control device detect slave devices inthe network.

Thus, it would be desirable to provide a method and apparatus forautomatically detecting slave devices in a network.

SUMMARY

A method and apparatus for detecting remote network devices in a networkis described. In one embodiment, a method for detecting remote networkdevices comprises detecting an event and, in response to detecting theevent, a) transmitting a message requesting a response from one or moreremote network devices, the message comprising a first networkidentification code, and b) determining whether a response to themessage has been received, the response transmitted by a remote networkdevice after receiving the message and determining that the firstnetwork identification code matches a second network identification codestored within the remote network device, the response comprisingidentification information of the remote network device. If c) aresponse has not been received, terminating the method for detectingremote network devices if a pre-determined time period has elapsed sincetransmitting the message. If d) a response has been received, storingidentification information associated with the responding remote networkdevice and repeating steps a-d until no further responses are received.

In another embodiment, an apparatus for detecting remote network devicesin a network comprises a memory for storing a first networkidentification code and identification information of any detectedremote devices, a transmitter for transmitting messages, and a receiverfor receiving messages. The apparatus further comprises a processor fordetecting an event and in response to detecting the event, a) causing atransmitter to transmit a message requesting a response from one or moreremote network devices, the message comprising the first networkidentification code and b) determining whether a response to the messagehas been received, the response transmitted by a remote network deviceafter receiving the message and determining that the first networkidentification code matches a second network identification code storedwithin the remote network device, the response comprising identificationinformation of the remote network device. If c) a response has not beenreceived, terminating the detection of remote network devices if apre-determined time period has elapsed since transmitting the message.If d) a response has been received, storing identification informationassociated with the responding remote network device and repeating stepsa-d until no further responses are received.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, advantages, and objects of the present invention willbecome more apparent from the detailed description as set forth below,when taken in conjunction with the drawings in which like referencedcharacters identify correspondingly throughout, and wherein:

FIG. 1 illustrates a network comprising two communication channels, anetwork control device and two remote network devices;

FIG. 2 is a functional block diagram of one embodiment of the networkcontrol device of FIG. 1 ;

FIG. 3 is a functional block diagram representing one embodiment of oneor both remote network devices shown in FIG. 1 ;

FIG. 4 is an illustration of a “short” data packet used in the system ofFIG. 1 ;

FIG. 5 is an illustration of a “long” data packet used in the system ofFIG. 1 ;

FIG. 6 is a flow diagram illustrating one embodiment of a methodimplemented by the network control device of FIG. 1 for using themessage structures shown in FIGS. 4 and 5 to assign a house code to thenetwork control device;

FIG. 7 is a flow diagram illustrating one embodiment of a methodimplemented by the network control device of FIG. 1 to discover otherdevices able to communicate with the network control device;

FIGS. 8 a and 8 b are flow diagrams illustrating one embodiment of amethod implemented by either of the remote network devices of FIG. 1 toregister with the network control device of FIG. 1 or another remotenetwork device;

FIG. 9 is a flow diagram illustrating another embodiment of a methodimplemented by either of the remote network devices of FIG. 1 toregister with the network control device of FIG. 1 or another remotenetwork device;

FIG. 10 is a flow diagram illustrating yet another embodiment of amethod implemented by either of the remote network devices of FIG. 1 toregister with the network control device of FIG. 1 or another remotenetwork device; and

FIG. 11 is a flow diagram illustrating another embodiment of a method1100 for self-assignment of a network code to a network device.

DETAILED DESCRIPTION

The present description relates to methods and apparatus for providingrobust communications between devices in a network. It should beunderstood that in some embodiments, the hardware described below may bedesigned and manufactured in compliance with one or more governmentalregulations that restrict operation of such devices. For example, in oneembodiment, the hardware is designed to meet the requirements of 47C.F.R. Part 95, a United States regulation promulgated by the FederalCommunications Commission. In another embodiment, the hardware isdesigned to meet the requirements of 47 C.F.R. Part 15.

FIG. 1 illustrates a network 100, which comprises a network controldevice 102, wired remote network device 104, wireless remote networkdevice 106, controlled electric device 108, powerline 110 disposedwithin wall 112, and wireless communication channel 114. It should beunderstood that network 100 may comprise any number of otherconfigurations, including configurations having a greater, or fewer,number and type of network devices and controlled electric devices. Eachof the network devices, i.e., network control device 102, wired remotenetwork device 104, and wireless remote network device 106, is typicallylocated many feet away from each other in proximity. For example,network control device 102 could be located in a kitchen, while wiredremote network device 104 could be located outdoors, and wireless remotenetwork device 106 located in a bedroom.

In one embodiment, network 100 is used by consumers to provide networkedcommand and control to household electric devices, such as indoor oroutdoor lighting, water pumps (i.e., pumps for pools, Jacuzzis,fountains, etc.), security devices, garage door openers, heating and airconditioning systems (including thermostats, fans, electric and gascentral heaters, portable heaters and air conditioners, appliances,communication devices, computers, video and still cameras, and othertypes of equipment. In other embodiments, network 100 can be configuredto provide networked command and control to larger entities, such asbusinesses, apartment buildings, sporting venues, etc.

Each of the network devices (i.e., network control device 102, wiredremote network device 104, and wireless remote network device 106) inFIG. 1 is generally able to communicate with each other, eitheruni-directionally bi-directionally. For example, in one embodiment,network control device 102 may transmit commands to wired remote networkdevice 104 and wireless remote network device 106 only. In anotherembodiment, network control device 102 may transmit commands to wiredremote network device 104 and wired remote network device 104 may beable to transmit status or acknowledgements back to network controldevice 102, while wireless remote network device 106 remains able toonly receive commands sent by network control device 102. Thus, anycombination of one-way or bi-directional communications are possibleamong devices in network 100.

Communications among the network devices may be transmitted over-the-airusing one or more well-known wireless communication techniques or theymay be transmitted using powerline 110, typically comprisingpre-existing high-power commonly found in homes, offices, businesses. Inanother embodiment, messages are transmitted over both communicationchannels, i.e., via both over-the-air communication channel 114 andpowerline 110, either simultaneously or in a time-multiplexed fashion.Thus, each device in network 100 may comprise circuitry to transmitand/or receive information using RF circuitry, powerline circuitry, orboth. In addition, devices may be configured to only receiveinformation, to only transmit information, to only receive informationusing powerline technology, to only receive using RF technology, to onlytransmit information using powerline technology, to only transmit usingRF technology, to transmit information using both powerline and RFtechnology, or any combination thereof.

Transmitting information over powerline 110 generally results inwireless propagation of such information along the length of powerline110. This wireless propagation may be received by devices in network 100equipped to receive only wireless transmissions although, generally,such a device must be located relatively close to powerline 110, sincethe level of electro-magnetic radiation may be limited by one or moregovernmental authorities.

Powerline 110 typically comprises a two or three-wire bundle ofconductors. For example, in a three-wire scheme, one conductor carries110 volts AC (commonly referred to as “hot”), one conductor acts as areturn, or neutral, and one conductor acts as a safety ground. Intwo-wire embodiments, generally only the “hot” and neutral wires arefound. Thus, transmitting communication signals over powerline 110provides a readily-accessible communication channel throughout homes andbusinesses over which to send communications.

In the embodiment shown in FIG. 1 , network control device 102 comprisesa central control device that sends messages to other network devices,such as wired remote network device 104 and wireless remote networkdevice 106. The messages may comprise commands that instruct othernetwork devices to perform various actions, such as provide or removepower to one or more electric devices 108, such as indoor or outdoorlighting, pumps, and security devices, or to control operation ofdevices, such as to pan or zoom a security camera, dim lights to acertain level, change the watering time and/or duration of sprinklers,as well as other actions that will be discussed later herein. Networkcontrol device 102 typically comprises a user interface comprising anelectronic display and means for entering commands/information, such asa keypad, microphone, touchpad, or any other well-known device forentering commands or information into network control device 102.

Commands may also comprise queries, instructing remote network devicesto provide information to a requesting device, such as identificationinformation (i.e., a serial number or house code), a location of thedevice, a status of the device or electric device 108 associated withthe device, etc. In one embodiment, such information is transmitted inmessages referred to as responses.

In another embodiment, one or more of the network devices shown in FIG.1 may not be configured to receive commands from network control device102. In this case, information is simply transmitted from such a deviceat predetermined time intervals or upon the occurrence of apredetermined event, or a combination of both. For example, wirelessremote network device 106 might comprise a wireless thermometer thattransmits a reading of the ambient air temperature to network controldevice 102 every 15 minutes or when a sudden increase in ambienttemperature is detected. In the embodiment shown in FIG. 1 , neitherwired remote network device 104 nor wireless remote network device 106comprise a user interface; they are controlled and operate withoutdirect user input. In other embodiments, network devices may comprise auser interface or other interfaces, such as a telephone interface, aserial port, a parallel port, an Ethernet interface, a USB interface, orany other interface that allows information to be sent to, or from,network devices.

Wired remote network device 104 and wireless remote network device 106may comprise (or be incorporated into) a variety of devices, such as anelectric switch (i.e., for controlling 110 VAC to various devices), alight, a thermometer, a thermostat, a video camera, a still camera, amicrophone, a water pump, a water heater, household appliances such asrefrigerators, freezers, ovens, microwave ovens, washers, dryers, solarenergy systems, or virtually any type of energy-consuming device.

FIG. 2 is a functional block diagram of one embodiment of networkcontrol device 102, shown as a having a user interface and multipletransmitters and receivers. Specifically, FIG. 2 shows processor 200,memory 202, user interface 204, modulator 206, demodulator 208, RFtransmitter 210, powerline transmitter 212, interface 214, RF receiver216, powerline receiver 218, wiring assembly 220, and wiring assembly222. It should be understood that not all of the functional blocks shownin FIG. 2 are required for operation of network control device 102 (forexample, interface 214 might not be used, only one type of transmittermay be present, only one type of receiver may be present, etc.), thatthe functional blocks may be connected to one another in a variety ofways, and that not all functional blocks necessary for operation ofnetwork control device 102 are shown (such as a power supply) forpurposes of clarity. It should also be understood that each device innetwork 100 may comprise certain core functionality blocks shown in FIG.2 , such as processor 200, memory 202, modulator 206 (for devicescapable of transmission), demodulator 208 (for devices capable ofreception), at least one type of transmitter (for devices capable oftransmission), and at least one type of receiver (for devices capable ofreception).

Processor 200 is configured to provide general operation of networkcontrol device 102 by executing processor-readable instructions storedin memory 202, for example, executable code. Processor 200 is typicallya general purpose processor, such as a PIC16F1938 microcontrollermanufactured by Microchip, Inc. of Chandler, Ariz.

Memory 202 comprises one or more information storage devices, such asRAM, ROM, EEPROM, UVPROM, flash memory, CD, DVD, Memory Stick, SDmemory, XD memory, thumb drive, or virtually any other type of memorydevice. Memory 202 is used to store the processor-readable instructionsfor operation of network control device 102 as well as any informationused by processor 200, such as data packet structure format, informationreceived from other network devices, device parameter information,device identification information, device status information, etc. Oneof the primary functions of processor 200 is to encode commands andinformation into data packets for transmission to other network devicesand to decode data packets received from those devices, as will beexplained in greater detail later herein.

User interface 204 is coupled to processor 200 and allows a user tocontrol operation of network control device 102, provide commands andinstructions to network control device 102, and receive information fromnetwork control device 102. User interface 204 typically comprises anelectronic display and means for inputting information into networkcontrol device 102. For example, the electronic display could compriseone or more seven-segment displays, a cathode ray tube (CRT), a liquidcrystal display (LCD), a light emitting diode display (LEDD), one ormore light emitting diodes (LEDs), light arrays, or any other type ofvisual display. Further, the electronic display could comprise an audiodevice, such as a speaker, for audible presentation of information to auser. Of course, the aforementioned items could be used alone or incombination with each other and other devices may be alternatively, oradditionally, used.

User interface 204 typically comprises means for entering informationinto network control device 102, such as a keypad, keyboard, microphone,etc. Of course, the means for entering information could be incorporatedinto the display device, such as the case in a touchscreen device.

Modulator 206 is used to modulate data packets received from processor200 for transmission to remote network devices. In one embodiment,modulator 206 comprises circuitry necessary to modulate information inaccordance with any single-carrier modulation technique, such as anyvariation of frequency-shift keying (FSK), amplitude modulation (AM), orphase-shift keying (PSK). However, other modulation techniques could beused in in the alternative, such as spread-spectrum techniques.

Demodulator 208 is used in applications where it is desirable to receivemessages from network devices. In one embodiment, demodulator 208comprises circuitry necessary to demodulate information encoded using asingle-carrier modulation technique, such as the aforementionedfrequency-shift keying (FSK), amplitude modulation (AM), or phase-shiftkeying (PSK). Other demodulation techniques could be used in thealternative.

Network control device 102 may additionally comprise interface 214 forallowing network control device 102 to communicate with other remotedevices, such as a mobile telephone, portable or fixed computer, remotecontrol, and/or other devices. As such, interface 214 comprisescircuitry in accordance with the selected interface technology, such asBluetooth, infrared, RF, Ethernet, wireless telephone protocols such asWIMAX, LTE, CDMA, GSM, and others. Interface 214 is coupled to processor200 to provide received information to processor 200 and to sendinformation from processor 200 to one or more remote devices. Forexample, interface 214 could be used to receive commands, instructions,and/or information from a home owner, home occupant, or other interestedparty to network control device 102 with regard to programming and/orcontrol of network control device 102, wired remote network device 104,and/or wireless remote network device 106.

The modulated data packets from modulator 206 is provided to at leastone transmitter. In the embodiment shown in FIG. 2 , the information isprovided to two transmitters, RF transmitter 210 and powerlinetransmitter 212. In this embodiment, both transmitters are used to sendinformation redundantly to remote devices in the network, generallysimultaneously, although it may be transmitted at different times inother embodiments.

The transmitters are typically controlled by processor 200. In oneembodiment, processor 200 instructs the transmitters to re-transmit themodulated data packets a number of times to increase the chance ofsuccessful reception.

RF transmitter 210 receives modulated information from modulator 206,comprising data packets for transmission to one or more remote devices.The information may comprise commands, instructions, data,acknowledgments, or any other type of information. In some cases, theamount and/or type of information may be limited by one or moregovernmental regulations, statues, or other restrictions.

In one embodiment, RF transmitter comprises circuitry necessary toupconvert the modulated information to a desired carrier frequency forwireless transmission to one or more network devices via antenna 222.Such circuitry is well known in the art. In other embodiments, RFtransmitter 210 comprises circuitry well-known in the art fortransmitting the information in accordance with other well-knowntransmission techniques, such as spread-spectrum techniques.

In one embodiment, RF transmitter 210 transmits the modulated,upconverted data packets at a relatively high power level for consumerdevices, up to approximately 4 watts. Prior-art consumer transmitterstypically transmit at very low power levels, to satisfy section 15 ofthe United States' Federal Communications Commission, more formallyknown as Title 47 Code of Federal Regulations Part 15. Part 15 is acommon testing standard for most electronic equipment sold in the UnitedStates, and covers the regulations under which an intentional,unintentional, or incidental radiator can operate without an individuallicense. Maximum transmission power under Part 15 is generally limitedto 10 milliWatts. However, under Title 47 C.F.R. Part 95 (“PersonalRadio Service”), transmitters can operate at up to 50 watts of power,thus allowing for a much greater signal coverage area and eliminatingthe need for costly repeaters, or having to settle for spotty andunreliable signal reception. The tradeoff for allowing such hightransmission power is that the emission bandwidth is limited to onlytens of kilohertz, typically between 4 and 25 kHz. For example, Part95.633(b) limits the bandwidth for any emission type to 8 kHz. Part 95additionally comprises other restrictions, such as the types of messagesthat may be transmitted, the type of information that may betransmitted, and other limitations. In an embodiment where RFtransmitter 210 is designed to comply with Part 95, a high transmissionpower may be achieved, but generally at the expense of a limitedtransmission bandwidth and potentially other restrictions. In otherembodiments, RF transmitter 210 may be designed to comply with Part 15,or some other FCC requirement. In yet other embodiments, RF transmitter210 may be designed without regard to FCC requirements if, for example,an associated network device is manufactured and/or sold in a countryoutside the United States. Most developed nations, however, impose somesort of requirements for wireless transmission.

Powerline transmitter 212 also receives the same modulated informationfrom modulator 206 and sends the modulated information to remote devicesvia powerline 110. The information may comprise commands, instructions,data, acknowledgments, or any other type of information. Modulatedinformation is received, upconverted, and coupled to powerline 110typically using one or more transformers, capacitors, diodes, inductors,and/or other well-known components.

Although the process of upconverting the modulated information has beendescribed as occurring independently within functional blocks 210 and212, it may occur in a circuit that is common to both functional blocks.

RF receiver 216 receives upconverted, modulated information sent byremote devices via antenna 222. The information may comprise commands,instructions, data, acknowledgments, or any other type of information.Again, in some embodiments, the amount and/or type of information may belimited by one or more governmental regulations, statues, or otherrestrictions. In one embodiment, RF receiver 216 comprises circuitrywell-known in the art for downconverting received RF signals andproviding the resulting downconverted signal to demodulator 108. Inother embodiments, RF receiver 216 comprises circuitry well-known in theart for receiving information in accordance with other well-knowntechniques, such as spread-spectrum signal reception.

Powerline receiver 218 generally receives the same upconverted,modulated information received by RF receiver 216, sent by remotedevices via a direct connection to powerline 110. RF receiver 218receives these signals via wiring assembly 220 connected to powerline110. Wiring assembly 220 typically comprises two or three insulatedconductors and a plug for physically connecting the powerline 110 topowerline receiver 218. Typically, powerline transmitter 212 andpowerline receiver 218 each use wiring assembly 220, because powerlinereceivers and transmitters are typically co-located, making a secondwiring assembly redundant and unnecessary. In one embodiment, theupconverted, modulated information received by powerline receiver 218 isdownconverted into a baseband signal, resulting in modulated information(i.e., data packets) that is provided to demodulator 208. Powerlinereceiver 218 comprises well-known circuitry, such as one or moretransformers, capacitors, diodes, inductors, and/or other well-knowncomponents, to downconvert the signals received over powerline 110.

In one embodiment, modulated data packets are provided to both RFtransmitter 210 and powerline transmitter 212 for simultaneoustransmission to one or more remote devices. In other embodiments, themodulated data packets are transmitted to one or more remote devicesusing either RF transmitter 210 or powerline transmitter 212.

FIG. 3 is a functional block diagram representing one embodiment of aremote network device 301, such as wired remote network device 104 orwireless remote network device 106, having bi-directional communicationscapability and actuator 304 for controlling an electric orelectro-mechanical device. Shown are processor 300, memory 302, actuator304, modulator 306, demodulator 308, RF transmitter 310, powerlinetransmitter 312, RF receiver 316, and powerline receiver 318. It shouldbe understood that not all of the functional blocks shown in FIG. 3 arerequired for operation of remote network device 301 (for example, onlyone type of transmitter may be present, only one type of receiver may bepresent, modulator 306, RF transmitter 310, and powerline transmitter312 may not be present (in an embodiment where remote network device 301lacks transmission capability), etc.). It should also be understood thatthe functional blocks shown in FIG. 3 may be connected to one another ina variety of ways, and that not all functional blocks necessary foroperation of remote network device 301 are shown (such as a powersupply, or wiring assembly(ies) related to powerline transmitter 312and/or powerline receiver 318) for purposes of clarity.

Processor 300, memory 302, modulator 306, demodulator 308, RFtransmitter 310, powerline transmitter 312, RF receiver 316, andpowerline receiver 318 have all been discussed previously with respectto FIG. 2 and their description applies directly to the components inFIG. 3 . Thus, a discussion of their functionality and structure willnot be repeated.

However, remote network device 301 typically comprises actuator 304.Actuator 304 typically comprises a switch that is used to control powerto one or more lights, transformers, pumps, motors, and other electricdevices. In other embodiments, actuator 304 comprises one of a varietyof other possible devices, such as a rheostat, a voltage-controlledoscillator (VCO), a variable capacitor, a motor, or any other devicethat can be controlled by signals from processor 300. Actuator 304typically receives a 110 VAC signal as an input and switchably providesthe 110 VAC signal to its output, where it is used to power an electricdevice. Control of actuator 304 is provided by one or more signals fromprocessor 300. For example, in an embodiment where actuator 304comprises a switch, a signal can be sent from processor 300 instructingactuator 304 to connect the 110 VAC on its input to its output. Inanother embodiment where actuator 304 comprises a rheostat, a signalfrom processor 300 may be used to alter the resistance between the inputand the output of actuator 304, thereby causing an output voltage tovary in accordance with the signal from processor 300.

In another embodiment, remote network device 301 comprises informationsource 320. Information source 320 comprises any device for providinginformation to processor 300, such as a thermometer, a sill or motionpicture camera, a transducer of any sort, a pressure gauge, an encoderfor determining a position of an object or mechanism, a tachometer, aflow sensor, or other data measurement and/or reporting device. Inanother embodiment, information source 320 comprises a device separateand distinct from remote network device 301, whereby information source320 provides information to processor 300 via wired or wireless meansthat is well-known in the art. Information source 320 may provideinformation to processor 300 at regular, or irregular time intervals,upon the occurrence of a predetermined event (such as a thresholdcondition being reached, i.e., an alarm condition), or when queried byprocessor 300. The query from processor 300 may be the result of networkcontrol device 102 or another remote network device requestinginformation from information source 320. The information frominformation source 320 is received by processor 300, where it istypically encoded into a data packet for transmission to network controldevice 102 and/or other remote network devices. In one embodiment, theinformation from information generator 320 is compared to one or morepredetermined thresholds and only transmitted if the informationrepresents a condition that exceeds the threshold. In anotherembodiment, information provided by information source 320 may beencoded using a predefined code, such as a look-up table. In thisembodiment, a digital code is used to represent the information, thuspotentially limiting the amount of information transmitted to anothernetwork device. For example, if information source 320 comprises athermometer, then processor 300 could use a look-up table having 256entries, each entry representing a unique potential temperature value.Processor 300 compares the information sent by information source 320and matches it to the closest value in the look-up table, thenconstructs a data packet comprising a code related to the closesttemperature value in the look-up table. In this way, the amount oftransmitted data and, perhaps, the data classification or type, mayconform to a required design constraint, such as those imposed bygovernmental authorities, for example.

FIG. 4 is an illustration of one embodiment of a data packet 400,referred to as a “short” data packet, used to convey information amongnetwork control device 102 and remote network devices. In oneembodiment, short data packet 400 comprises 4 bytes, each bytecomprising 8 bits. The size of short data packet 400 is relativelysmall, thereby limiting the necessary transmission bandwidth andallowing for quick transmission. Short data packet 400 typically istransmitted with a need for acknowledgement.

Short data packet 400 comprises a number of fields 402-410, each fieldfor specifying a certain characteristic of the data packet, for example,a command, a response, information, data, error checking information,etc.

Field 402, labeled “House Code,” is a network identification code, suchas an address, that is generally pre-assigned to network control device102 and remote network devices. Devices having the same house code canbe thought of belonging to the same network so that they may communicatewith each other. Each data packet comprises a house code that instructsnetwork devices having the same house code to process the data packet.For example, if wired remote network device 104 and wireless remotenetwork device 106 both are pre-assigned a house code of 0xE4, networkcontrol device 102 may communicate with both remote network devices byinserting 0xE4 into field 402. If wired remote network device 104 andwireless remote network device 106 are assigned different house codes,data packets may be sent to each device individually by inserting theirrespective house codes into respective data packets. Remote networkdevices having the same house code may also be addressed individually ifsome other identification information is known about each device, suchas a serial number associated with each remote network device.

In general, devices in network 100 will only respond to messages sentthat match their assigned house code. In one embodiment, however,devices will respond to messages sent to any house code if it isdetermined that a device's house code is a default house code.Alternatively, or in addition, a device will respond to a house codethat is designated as a “universal” house code, i.e., a house codeinstructing devices to respond no matter what their assigned house codemay be.

Device groups may be defined by assigning several devices to one housecode and several others to another house code. Additional groups may beadded as well. For example, two remote network devices could be assigneda house code of 0x3A, three other remote network devices could beassigned a house code of 0x22, and yet another remote device could beassigned a house code of 0xB1. A network control device 102 could thenaddress the three groups individually using the house code assigned toeach group.

Field 404 is one bit in length and represents whether a data packet is a“short” data packet or a “long” data packet. A long data packet isdescribed more fully later herein.

Field 406, labeled “Short Command,” is, in one embodiment, a seven bitfield which represents one of 128 different pre-defined messages (i.e.,commands or responses) that may be transmitted between devices innetwork 100. Table 1 defines twelve such predetermined short messagesavailable in one embodiment. The term “short command” is used to denotemessages used in conjunction with short data packet 400. Commandsgenerally instruct another device to perform an action, such as toactuate a switch resulting in an electric device being turned on or off,such as a light, a pump, a fan, an air conditioner, a heater, etc.,transmit an acknowledgment message, change the device's house code,report the device's house code, group number, or device type, report astatus of the device or equipment associated with the device, report anoperating parameter or condition associated with the device itself or arelated electrical or mechanical component associated with the device,such as a mechanical or electrical parameter such as a voltage, acurrent, a switch status (i.e., open or closed), a temperature, apressure, a position, etc. Responses are generally transmitted by adevice in response to receiving a command, although they can betransmitted autonomously as well (an example being the transmission of adevice house code at predetermined time intervals). One example of aresponse is an acknowledgment of receipt of a command that may, or maynot, contain data associated with the acknowledgement. Often, responsescontain data that was requested by a command, such as the device's housecode, the status of the device, an operating parameter or conditionassociated with the device itself or a related electrical or mechanicalcomponent associated with the device, such as a mechanical or electricalparameter such as a voltage, a current, a switch status (i.e., open orclosed), a temperature, a pressure, a position, etc. Sometimes, thedifference between a command and a response is a matter of semantics.For example, a command may be defined as a message transmitted fromdevice A to device B requesting that device B send device B's serialnumber to device A. A response may be defined as device B sending itsserial number to device A, but also requesting an acknowledgement fromdevice A that the serial number was received. Another response may bedefined as device A transmitting an acknowledgement to device B,indicating receipt of the serial number.

TABLE 1 Short Messages Message Name Data Description 0x1HOUSE_CODE_QUERY 0x00 Request devices having certain house code torespond 0x2 HOUSE_CODE_RESPONSE 0x00 Response from devices toPLC_CMD_HOUSE_QUERY 0x3 HOUSE_CODE_SET House Set all devices in networkto Code new house code 0x4 SERIAL_NUM_RESET 0x00 Reset serial numberdiscovery flag in device 0x5 SERIAL_NUM_QUERY 0x00 Query all devices forcurrent serial number 0x6 LEARN_MODE_ON 0x00 Devices will enter into aconfiguration mode used to assign devices to a group 0x7 LEARN_MODE_OFF0x00 Devices will exit configuration mode 0x8 DEVICE_TYPE_QUERY 0x00Request devices in given house code to respond (ACK) 0x9DEVICE_TYPE_SN_QUERY 0x00 Request devices in given house code to respond0xA GROUP_CHANGE Group No. Devices will enter into a configuration modewhere parameter changes to devices in the given group will be stored 0xBGROUP_CHANGE_ON Group No. Turn given group on 0xC GROUP_CHANGE_OFF GroupNo. Turn given group off

Field 408, labeled as “Data Byte,” is, in one embodiment, an eight bitfield reserved for sending information related to each particularmessage. Such information may comprise a house code, an operatingstatus, a parameter, visual information, audio information, asub-command, a serial number, a time, a date, a group number, a devicetype, or virtually any other type of information.

Field 410, labeled as “CRC”, is an error-checking field used todetermine the integrity of data packet 400 upon receipt. In oneembodiment, error-checking comprises the well-known cyclic redundancycheck (CRC), although in other embodiments, other error-checking methodsmay be used. The information contained within field 410 may be commonlyreferred to as a checksum.

FIG. 5 is an illustration of one embodiment of a “long” data packet 500,used to convey information among network control device 102 and remotenetwork devices. In one embodiment, long data packet 500 comprises up to21 bytes, each byte comprising 8 bits. The size of long data packet 500is greater than short data packet 400, allowing for more information tobe transmitted in each data packet. Long data packets typically takelonger to process than short data packets, therefore it may be desirableto limit their use, such as to only use long data packets during aone-time device setup and installation.

Long data packet 500 comprises a number of fields 502-518, each fieldfor specifying a certain characteristic of the data packet, for example,a command, a response, information, data, error checking information,etc.

Field 502, labeled “House Code,” is an identification code, such as anaddress, that is pre-assigned to each of the remote devices in network100. This field is similar to field 402 shown in FIG. 4 and describedabove.

Field 504 is similar to field 402 above, and represents whether eachdata packet is a “short” data packet or a “long” data packet.

Field 506, labeled “SEQ,” is a one-bit field for identifying whether thedata packet is part of a sequence of data packets being transmitted. Inone embodiment, each data packet that is related to another data packetis assigned a “1” in the field 506. In one embodiment, the first byte indata field 516 identifies a source address of the device transmittingthe sequence of data packets. In one embodiment, the source addresscomprises the house code of the device. Data packet sequences are usedto transmit information that is too large to be placed into a singlelong data packet, enabling system flexibility to add additionalmessaging capabilities in the future.

Field 508, labeled “LAST”, is a field used in conjunction with field506, described above, to indicate that a data packet is the last datapacket in a sequence of data packets. In one embodiment, field 508comprises one bit that is set to “1” to indicate that the data packet isthe last data packet in a sequence.

Field 510, labeled “ACK”, is a field that generally used to acknowledgereceipt of a message, (i.e., a query or command from another device onnetwork 100). In one embodiment, field 510 is one bit long and is set toa “1” to denote that the data packet is an acknowledgement message.Typically, acknowledgement messages will not have any information placedinto data field 516. In other embodiments, data packets may sometimescomprise information relating to the acknowledgement. For example, aserial number, a house code, a voltage, an RPM, a mechanical orelectrical status, or virtually any other information, could be insertedinto field 516 in an acknowledgement message.

Field 512, labeled “DATA SIZE”, is used to denote the amount ofinformation in field 516, for example a number of bytes. In oneembodiment, field 512 is 4 bits long, allowing for 16 possibleindications of data size in field 516.

Field 514, labeled “COMMAND” is, in one embodiment, an eight bit fieldwhich represents one of 256 possible pre-defined “long” messages (i.e.,commands or responses) that may be transmitted among devices in network100. Table 2 illustrates one embodiment defining nine “long” messages.

TABLE 2 Long Messages Message Name Description 0x0 PING Ping devicespecified device 0x1 GET_HOUSE_CODE Get house code of specified device0x2 SET_HOUSE_CODE Set house code of specified device 0x3SEND_SERIAL_NUM Serial number of device is transmitted 0x4 GET_GROUP Getdevice group number 0x5 SET_GROUP Set device group number 0x6PARAM_CHANGE Change parameter of device 0x7 GET_STATUS Get status ofdevice 0x8 GET_TYPE Get device type

The term “long messages” is used to denote messages used in conjunctionwith long data packet 500. Commands generally instruct another device toperform an action, such as actuate a switch resulting in an electricdevice being turned on or off, such as a light, a pump, a fan, an airconditioner, a heater, etc., change the device's house code, report thestatus of the device, report an operating parameter or conditionassociated with the device itself or a related electrical or mechanicalcomponent associated with the device, such as a mechanical or electricalparameter such as a voltage, a current, a switch status (i.e., open orclosed), a temperature, a pressure, a position, etc. Responses aregenerally transmitted by a device in response to receiving a command,although they can be transmitted autonomously as well (an example beingthe transmission of a device house code at predetermined timeintervals). One example of a response is an acknowledgment of receipt ofa command that may, or may not, contain data associated with theacknowledgement. Often, responses contain data that was requested by acommand, such as the device's house code, the status of the device, anoperating parameter or condition associated with the device itself or arelated electrical or mechanical component associated with the device,such as a mechanical or electrical parameter such as a voltage, acurrent, a switch status (i.e., open or closed), a temperature, apressure, a position, etc. Sometimes, the difference between a commandand a response is a matter of semantics. For example, a command may bedefined as a message transmitted from device A to device B requestingthat device B send device B's serial number to device A. A response maybe defined as device B sending its serial number to device A, but alsorequesting an acknowledgement from device A that the serial number wasreceived. Another response may be defined as device A transmitting anacknowledgement to device B, indicating receipt of the serial number.

Field 516, labeled “DATA”, comprises information relating to variousmessages. In the embodiment shown in FIG. 5 , field 516 comprisesmultiple bytes. In one embodiment, field 516 may comprise from 1 up to16 bytes of data. The information contained within field 516 maycomprise virtually any type of data, including a device serial number, adevice house code, an operating parameter or condition associated withthe device itself or a related electrical or mechanical componentassociated with the device, such as a mechanical or electrical parametersuch as a voltage, a current, a switch status (i.e., open or closed), atemperature, a pressure, a position, visual information, audioinformation, a sub-command, a time, a date, a group number, a devicetype, or virtually any other type of information

Field 518 labeled as “CRC”, is, in one embodiment, a two-byteerror-checking field used to determine the integrity of data packet 500upon receipt. In one embodiment, error-checking comprises the well-knowncyclic redundancy check (CRC), although in other embodiments, othererror-checking methods may be used. The information contained withinfield 518 may be commonly referred to as a checksum.

FIG. 6 is a flow diagram illustrating one embodiment of a method 600,typically implemented by network control device 102, for using themessage structures described above to self-assign an initial house codeor network identification code, to itself at a location, such as a home,office, or other structure or surrounding area of such locations. Theprocess may also be implemented by wired remote network device 104 orwireless remote network device 106. As such the term “device” will beused with respect to method 600, encompassing network control device102, wired remote network device 104, and wireless remote network device106. As discussed previously, house codes are used to define a networkof devices, each device in a network having the same house code.

Processing begins in block 602, where the device is powered on.

In block 604, a processor within the device determines a house codestored within a memory of the device.

In block 606, the processor determines whether the house code is adefault house code assigned to the device, generally during themanufacturing process. In one embodiment, a default house code ispredetermined to equal 0xFF. Thus, if the processor determines that thehouse code stored in the memory is equal to 0xFF, it is assumed that thehouse code is a default house code, and that the device is beinginitialized for the first time. Processing then continues to block 608.If the processor determines that the house code is not thepredetermined, default house code, then it is assumed that the newdevice has been previously installed and initialized, and process 600terminates at block 610.

In block 608, the processor initializes a counter to a predeterminednumber, generally to a number that corresponds to a minimum value that ahouse code could be assigned. In this example, the counter is set to0x01.

In block 612, the processor generates a message to determine whetherthere are any other devices within range of the device. The processorthen causes the transmitter to transmit the message. For example, theHOUSE_CODE_QUERY described in Table 1 could be transmitted, eitherover-the-air, over powerline 110, or both, as described earlier. Themessage comprises a house code equal to the value of the counter. Themessage is sent by the device, instructing any other device able toreceive the message to transmit a response identifying a house codecurrently assigned to the responding device. For example, theHOUSE_CODE_RESPONSE described in Table 1 might be transmitted inresponse to another device receiving the HOUSE_CODE_QUERY message. TheHOUSE_CODE_QUERY comprises the house code assigned to the respondingdevice. After the message is transmitted, processing continues to block614.

In block 614, the processor determines if any responses (such as theHOUSE_CODE_RESPONSE message) are received in response to transmittingthe message in block 612. Messages may be received over-the-air, viapowerline 110, or both, as described earlier. If a response is received,it is an indication that another device is operating with the house codetransmitted in step 612 and not available for the device to use.Processing continues to block 616, where the counter is incremented.Processing then returns to block 612, where another message istransmitted to determine if any other devices are within range of thedevice is using a house code equal to the value of the incrementedcounter.

Returning to block 614, if the processor does not determine that anyresponse has been received as a result of the message transmitted instep 612, processing continues to block 618.

In block 618, the device's house code is set to a value related to thevalue of the counter. In one embodiment, the device's house code is setto the value of the counter. Processing optionally proceeds to block620.

In block 620, the processor generates a command, instructing any devicecapable of receiving the command to change their respective house codesto the house code identified at block 618. The processor then causes thetransmitter to transmit the command. For example, the HOUSE_CODE_SETcommand, described in Table 1, could be used. The HOUSE_CODE_SET commandcomprises a data field (field 408) where the house code determined inblock 618 is placed. Other devices that receive this message having adefault house code will set their house code to the one in theHOUSE_CODE_SET command, either in field 408 or in field 402.

FIG. 7 is a flow diagram illustrating one embodiment of a method 700,typically implemented by network control device 102, although it couldbe executed by wired remote network device 104 or wireless remotenetwork device 106 as well. As such the term “device” will be used withrespect to method 700, encompassing network control device 102, wiredremote network device 104, and wireless remote network device 106.Process 700 may be referred to as “device discovery.”

The method beings at block 702, where, in one embodiment, a processorwithin the device monitors a clock to determine whether to continueprocessing to block 704. Executable code stored within a memoryinstructs the processor to continue to block 704 if the clock indicatesthat a predetermined time period has elapsed, such as a twelve hour timeperiod or if the clock indicates one or more predetermined actual times.

In another embodiment, the processor determines whether a predeterminedevent has occurred as directed by the processor-executable instructionsstored in the memory. Such a predetermined event, in one embodiment,includes receipt of a signal from another device. In other embodiments,the predetermined event is a power-up event or detection of anelectrical or mechanical condition.

In still another embodiment, alternatively or in addition to theembodiments described above, the method 700 continues to block 704 ifthe processor is given a command to do so by a user of the device. Forexample, after a user installs a remote device within communicationrange of a network control device 102, the user may provide anindication, via a user interface such as user interface 204, forprocessing to proceed to block 704. In one embodiment, the indication isgenerated when the user initiates a predefined action, such as pressingtwo buttons located on the device for more than a predetermined timeperiod, such as three seconds. When the processor detects thiscondition, processing continues to block 704.

In block 704, an electronic counter is initialized, using well-knowntechniques in either in software, hardware, or both.

Processing continues to block 706, where the counter is incremented. Inanother embodiment, the counter is decremented.

In another embodiment, a random house code is generated by the processorin block 704 and block 706 is omitted. This is an alternative to using acounter to generate house codes.

Processing continues to block 708, where the processor generates amessage requesting any other device having a house code equal to a housecode within the message respond to the request with a respective deviceserial number. The processor then causes the transmitter to transmit themessage. For example, the SERIAL_NUM_QUERY described in Table 1 could betransmitted, either over-the-air, over powerline 110, or both, asdescribed earlier. Each device in the network typically comprises apre-assigned device serial number. In one embodiment, the device serialnumber comprises a four byte hexadecimal sequence, allowing for overfour billion unique serial numbers to be assigned to devices, typicallyduring the manufacturing process. In another embodiment, the serialnumber comprises a Media Access Control (MAC) address. In oneembodiment, the message transmitted in block 708 comprises the housecode assigned to the transmitting device, and directs any devices havingthe same house code to transmit their device serial number to therequesting device.

In block 710, the processor determines whether or not a response wasreceived from another device. In one embodiment, the processor will waitfor a predetermined time period after incrementing the counter beforemaking the determination, for example, 1.5 seconds. In anotherembodiment, the processor waits for a longer predetermined time period,for example one minute, and if no response is received, it is assumedthat no devices are active within range of the requesting device, andprocessing terminates at block 718.

Each of the other devices in network 100 is configured to send aresponse to the request transmitted in block 708 by transmitting aserial number pre-assigned to each device. For example, in oneembodiment, the SEND_SERIAL_NUM command described in Table 2, above, istransmitted by each device upon receipt of the request. TheSEND_SERIAL_NUM command comprises four bytes for sending the serialnumber of the device back to the master device.

In one embodiment, each device is configured to transmit the response apredetermined number of times in case one response “collides” withanother response sent by a different device. In this way, the responsemessage is much more likely to be received properly. The responses aretypically transmitted at random times to minimize the likelihood ofcollisions.

Returning now back to block 710, if no response is received within the(shorter) predetermined time period, processing continues to block 712,where the value of the counter in block 706 is compared to apredetermined value stored in the memory of the master device, forexample, the number 10. If the predetermined time period is equal to 1.5seconds, and the predetermined number is 10, then the processor willhave waited at least a total of 15 seconds for at least one device torespond to the request transmitted in block 708. If a greater timeperiod is desired, either the predetermined time period can beincreased, the predetermined number can be increased, or both.

If the counter value is not greater than the predetermined number,indicating that the processor has not waited long enough for at leastone response to be received, processing loops back to block 706, wherethe counter is incremented, and blocks 708 through 712 are repeated, ifnecessary.

Returning to block 710 once again, if a response from another device isreceived within the predetermined time period after incrementing thecounter, processing continues to block 714.

In block 714, the processor may generate an acknowledgement message toacknowledge receipt of the response. This message indicates that theresponse sent by the other device was successfully received by therequesting device. In one embodiment, the SEND_SERIAL_NUM responsedescribed in Table 2, above, is transmitted. This response messagediffers from the previous SEND_SERIAL_NUM command by having the ACK bitset in field 512, while no data fields 516 exist (or no data is insertedinto a single data field). Upon receipt of the acknowledgement message,a device may discontinue transmitting its serial number if it has notyet transmitted all of its predetermined number of re-transmissions,described below with regard to FIG. 10 .

In block 716, the processor stores the serial number contained in themessage received in block 710 in the memory. Other information may bestored in association with the serial number, such as the date and/ortime that the serial number was received, an indication of the type ofdevice that sent the received message, and/or any other characteristicsrelated to the other device. Such additional information may becontained in the response message received in block 710 or it may betransmitted in a subsequent message.

Processing then continues back to block 704, where the counter is onceagain initialized (or in another embodiment, a random house code isgenerated). Blocks 704 through 716 are then repeated until no furthermessages from other devices are received. At that point, the counter atblock 712 will have exceeded the predetermined value, and processingwill end at block 718. Thus, at the completion of method 700, therequesting device will have discovered all other devices in network 100using the same house code as the requesting device, and a serial numbercorresponding to each of the discovered devices.

FIGS. 8 a and 8 b are flow diagrams illustrating one embodiment of amethod 800, typically implemented by a remote network device such aswired remote network device 104 or wireless remote network device 106,for using the message structures described above to register with, or bediscovered by, other devices able to communicate with the remote networkdevice, such as network control device 102 or another remote device.

The process begins in block 802 when the remote network device ispowered on.

In block 804, a processor within the remote network device determines ahouse code stored within a memory of the device. The house code may beprovided to a display associated with the remote network device for theconvenience of a user of the device.

In block 806, the processor determines whether the device house code isa default house code assigned to the device, generally during themanufacturing process. In one embodiment, a default house code ispredetermined to equal 0xFF. Thus, if the processor determines that thehouse code stored in the memory is equal to 0xFF, then that is anindication that the device is being installed for the first time, andprocessing continues to step 808. If the processor determines that thehouse code is not the default house code, then it is assumed that theremote network device has been previously installed, and processingcontinues to block 810.

In block 810, the user may reset the house code. This may be desired,for example, if the remote network device was previously installed in aprior network or location and is now being installed into a new networkor location. A user interface on the device will typically allow such areset. In other embodiments, the device may comprise a switch, sensor,or electronic interface that could be used to provide a reset command tothe processor. If the house code is reset, processing continues to block808. Otherwise, processing for the method terminates at block 812, wherethe device retains its house code.

In block 808, the processor generates a message indicating that theremote network device seeks registration with a network control device102 or some other remote network device. The processor causes thetransmitter to transmit the message either over-the-air, over powerline110, or both. In one embodiment, the message comprises theHOUSE_CODE_QUERY described in Table 1. This message may comprise a 0xFFhouse code in field 402 and/or field 408 if the message is transmittedas a short message or in field 502 and/or 516 if the message istransmitted as a long message. In the case of a long message, the devicemay insert its pre-assigned serial number into data field 516 foridentification to other devices that receive the message. In anotherembodiment, a new message is defined, not shown in either Table 1 orTable 2, having a unique command that indicates that the device is newand requesting registration with a network control device 102 or someother remote network device.

In block 814, the processor determines whether a response to thetransmission at block 808 has been received. If not, it is an indicationthat no other device is within range of the remote network device, andprocessing continues to step 816, where, in one embodiment, theprocessor assigns a random house code to the device and stores the housecode in the memory. In another embodiment, if no response is receivedwithin a predetermined time period, no new house code is assigned to thedevice, and the device retains its default house code, as shown in block818. An alert may be generated to indicate to a user that the devicefailed to register. The alert may comprise an electrical signal used toilluminate a light on the device, produce a sound from the device,and/or transmit an error message to a pre-designated telephone number oran email address.

If a response to the message sent in block 808 is received in block 814,processing proceeds to block 820, as shown in FIG. 8 b . Messages may bereceived over-the-air, via powerline 110, or both, as described earlier.In one embodiment, the response comprises the HOUSE_CODE_SET messagedescribed in Table 1, instructing the device to change its default housecode to one specified in the HOUSE_CODE_SET message. In otherembodiments, other messages may be defined that instructs the device tochange its house code to one found in the message.

In block 820, the processor determines whether any additional messageshave been received in response to the message sent in block 808. Thiscould occur if, for example, the remote network device is within rangeof two or more network control devices 102, where each network controldevice 102 transmits a message to the device in response to receivingthe message sent in block 808. The processor typically waits for apredetermined time period to determine whether it has received more thanone message. If no other messages are received within the predeterminedtime period, i.e., only one response message is received, processingproceeds to block 822, where the house code contained in the response isstored within the memory, thereby replacing the default house code withthe one received in the response.

If more than one response is received at block 820, processing continuesto block 824, where the default house code in the memory is retained,due to the conflict of receiving more than one response to the messagetransmitted in block 808. An alert may be generated in block 826,providing an indication that multiple messages were received during theinitialization process.

In one embodiment, processing continues to block 830, where a manualhouse code selection is received from a user of the device via a userinterface. The manual house code selection is an indication of whichhouse code, selected from the received messages, the user wishes toassign to the device. Typically, the user will assign a house coderelating to a house code used by a network control device 102 owned bythe user. The user interface will typically display each of the receivedhouse codes, allowing the user to conveniently select one of them.

In block 832, the default house code stored in the memory is changed tothe house code selected by the user.

In another embodiment, after block 826, processing proceeds to block834, where input is received from a user, placing the device into analternative operating mode. The alternative operating mode instructs theprocessor to determine when a predefined message has been received froma network control device 102.

After placing the remote network device in the alternative operatingmode, the user places the network control device 102 into an operatingmode whereby network control device 102 transmits a predefined messageinstructing the remote network device to change its house code to ahouse code contained within the predefined message. The predefinedmessage transmitted by network control device 102 is a different messagethat what is received in block 814 and/or 820. For example, a predefinedmessage may comprise a pre-defined command for placement in field 406,instructing any device in the alternative operating mode to change theirhouse code to the one found in field 402. Typically, the predefinedmessage is transmitted repeatedly until either a device responds or atime-out condition is reached.

Meanwhile, the remote network device monitors for the predefined messagefrom the selected network control device 102 at block 836. If apredefined message is received from the selected 102, processingcontinues to block 838.

In block 838, the processor in the device retrieves a new house codeprovided in the predefined message and stores the new house code in thememory in block 840. After storing the new house code, processingcontinues to block 842.

In block 842, a message is generated by the processor transmitted fromthe remote network device to the network control device 102, instructingthe network control device 102 to exit the alternative operating modeand cease transmission of the predefined message. Such a message maycomprise a simple “acknowledgement” message.

The process of device registration then terminates at block 844, and thedevice typically exits the alternative operating mode automatically.

FIG. 9 is a flow diagram illustrating one embodiment of a method 900,typically implemented by a remote network device such as wired remotenetwork device 104 or wireless remote network device 106, for using themessage structures described above to register with, or be discoveredby, other devices able to communicate with the remote network device,such as network control device 102 or another remote device.

Processing begins in block 902, where input is received from a user,placing the remote network device into an alternative operating mode.The alternative operating mode instructs the processor within the remotenetwork device to determine when a predefined message has been receivedfrom a network control device 102 or other remote network device.

In block 904, the processor monitors for receipt of the predefinedmessage from a selected network control device 102 or other remotedevice. The predefined message is one that is transmitted from theselected network control device 102 or other remote network device, asexplained below.

After placing the remote network device in the alternative operatingmode at block 902, the user places the selected network control device102 or other remote network device into an operating mode wherebynetwork control device 102 or other remote network device transmits thepredefined message instructing any device operating in the alternativeoperating mode to change its house code to a house code contained withinthe message (this message is not defined in either Table 1 or Table 2).For example, a predefined message may be defined comprising a uniquecommand for placement in field 406, instructing any device in thealternative operating mode to change their house code to the one foundin field 402. The predefined message is typically transmittedrepeatedly.

In block 908, the predefined message sent from network control device102 or remote network device is received by the remote network deviceand identified by the processor.

In block 910, the processor retrieves a new house code provided by thepredefined message and stores the new house code in the memory in placeof the old or default house code.

In block 912, a message is transmitted from the remote network device tothe network control device 102 or other remote network device,instructing the network control device or other remote network device toexit the alternative operating mode and cease transmission of thepredefined message. Such a message may comprise a simple“acknowledgement” message.

In block 914, in one embodiment, remote network device registrationterminates, whereby the remote network device generally exits thealternative operating mode automatically after transmitting the messagein block 912.

FIG. 10 is a flow diagram illustrating one embodiment of a method 1000,typically implemented by a remote network device such as wired remotenetwork device 104 or wireless remote network device 106, for using themessage structures described above to register with, or be discoveredby, other devices able to communicate with the remote network device,such as network control device 102 or another remote device. Thisprocess is used in conjunction with the method described with respect toFIG. 7 and is typically used after a remote network device been assigneda house code by a network control device 102 or another remote networkdevice.

The process begins at block 1002, where the remote network devicereceives a message, query, or command from network control device 102,requesting that any receiving device having a particular house coderespond to the message, query, or command with information identifyingeach particular device. For example, the identifying information maycomprise a device name, a device description, a device serial number, adate and/or time relating to when the device was first powered on, whenthe device was first registered within network 100, or a combination ofthese and/or other information. In one embodiment, the message comprisesthe SERIAL_NUM_QUERY described in Table 1, above.

In one embodiment, only devices having an assigned house code stored inmemory matching a house code within the message respond to the messagereceived in block 1002.

After receiving the message in block 1002, processing continues to block1004, where the processor checks to see if the remote network device haspreviously successfully registered with, or been discovered by, networkcontrol device 102 or another remote network device. If the remotenetwork device has not previously successfully registered, processingcontinues to block 1006. If the remote network device has previouslysuccessfully registered, there is no need for the device to continuewith the remainder of method 1000, so the process terminates in step1018. The processor determines whether the remote network device haspreviously registered with the network control device or other remotenetwork device by checking the memory to see if an indication has beenpreviously stored that the remote network device has previouslysuccessfully registered. Such an indication is discussed with respect toblock 1016, below.

In block 1006, processing is delayed by a randomly-generated timeperiod. Such a randomly-generated time period may be obtained usingtechniques well-known in the art. The random nature of the delayprovides time diversity between messages sent by multiple devicesattempting to respond to the query in block 1002.

After the delay in block 1006, processing continues to block 1008, wherethe remote network device transmits the identifying information to thenetwork control device 102, either over-the-air, over powerline 110, orboth, as described previously.

At block 1010, processing is delayed by a predetermined time period toallow time for an acknowledgement message to be received in response tothe transmission in block 1008. For example, the predetermined timeperiod could comprise a value between half a second and 10 seconds.

In block 1012, a processor within the remote network device determineswhether the acknowledgement message has been received from the networkcontrol device 102 or other remote network device in response to sendingthe identification information in block 1008. The acknowledgment messagesignifies that the network control device or other remote network devicesuccessfully received the transmitted identification information. If noacknowledgement message is received, processing continues to block 1014.

In block 1012, the processor determines whether a predetermined numberof failures has occurred at block 1012, typically by using a counter totrack the number of times the “No” branch has been taken and comparingthat number to a predetermined number. If the number of failures atblock 1012 does not exceed the predetermined number, then processingcontinues back to block 1006, where another random delay is determined,and blocks 1008 through 1012 are repeated. In another embodiment,processing reverts to block 1008 instead of block 1006, where theidentification information is transmitted without calculating anotherrandom delay.

Back in block 1014, if the number of failures at block 1012 exceeds thepredetermined number, it is an indication that the identificationinformation is not being received by the network control device orremote network device after repeated efforts, so the remote networkdevice stops trying to send the identification information andprocessing terminates at block 1018.

Back in block 1012, if an acknowledgement message is received from thenetwork control device or other remote network device, it is anindication that the identification information transmitted in block 1008was successfully received. In that case, processing continues to block1016.

In block 1016, an indication is stored in the memory that the remotenetwork device has successfully registered with the network controldevice or other remote network device. The indication typicallycomprises a flag, or bit, that is set in the memory. In one embodiment,the indication is set for a predetermined time period, for example onehour, before it is automatically cleared. The process 1000 thenterminates in block 1018.

FIG. 11 is a flow diagram illustrating another embodiment of a method1100, typically implemented by network control device 102, although itcould be executed by wired remote network device 104 or wireless remotenetwork device 106 as well, for self-assignment of a network code, orhouse code, to a network device. As such, the term “device” will be usedwith respect to method 1100, encompassing network control device 102,wired remote network device 104, and wireless remote network device 106.

The method beings at block 1102, where, in one embodiment, a processorwithin the device monitors a clock to determine whether to continueprocessing to block 1104. Executable code stored within a memoryinstructs the processor to continue to block 1104 if the clock indicatesthat a predetermined time period has elapsed, such as a twelve hour timeperiod or if the clock indicates one or more predetermined actual times.

In another embodiment, the processor determines whether a predeterminedevent has occurred as directed by the processor-executable instructionsstored in the memory. Such a predetermined event, in one embodiment,includes receipt of a signal from another device. In other embodiments,the predetermined event is a power-up event or detection of anelectrical or mechanical condition.

In still another embodiment, alternatively or in addition to theembodiments described above, the method 1100 continues to block 1104 ifthe processor is given a command to do so by a user of the device. Forexample, after a user installs a remote device within communicationrange of a network control device 102, the user may provide anindication, via a user interface such as user interface 204, forprocessing to proceed to block 1104. In one embodiment, the indicationis generated when the user initiates a predefined action, such aspressing two buttons located on the device for more than a predeterminedtime period, such as three seconds. When the processor detects thiscondition, processing continues to block 1104.

In block 1104, the processor generates a message that instructs anyremote device who receives it to respond with their respective housecode. The processor further causes a transmitter to transmit themessage, either over-the-air, over powerline 110, or both, as describedearlier. Normally, remote devices will only respond to messages thatcomprise a house code matching their assigned house code. However, inone embodiment, one house code may be designated as a “universal” housecode that instructs remote devices to take an action no matter whattheir pre-assigned house code may be. For example, house code 0x00 couldbe pre-designated as a “universal” house code, so that when a remotedevice receives a message comprising house code 0x00, it will respond tothe message no matter what its pre-assigned house code may be.

One problem with requesting many remote devices to respond to themessage transmitted in block 1104 is the potential for messagecollision, as responses from multiple remote devices may be receivedsimultaneously. To combat this problem, each remote device in thenetwork may be programmed with a different delay period for respondingto either all messages or just messages designated for all remotedevices to respond. In this way, messages received by the requestingdevice will be received at different times, allowing for successfulreception of messages. In another embodiment, each remote device may beprogrammed to delay transmission of a response for a randomly-generatedtime period.

In one embodiment, remote devices respond only once to the messagetransmitted in block 1104 and ignore subsequently-transmitted messagesfor a predetermined time period after receipt of an initial message. Inanother embodiment, remote devices repeatedly transmit responses untilan acknowledgement message is received from the requesting device.

The responses sent by remote devices each comprise a house code assignedto the particular remote device sending the response.

Referring back to FIG. 11 , Processing continues to block 1106, where anoptional time delay is encountered. The time delay allows a time periodfor remote devices to respond to the message transmitted in step 1104.

In block 1108, the processor determines whether or not one or moreresponses were received from at least one remote device. If one or moreresponses were received, processing continues to block 1112.

In block 1112, the processor removes the house code found in thereceived response message(s) from consideration as a potential housecode for self-assignment. The processor may store the received housecode(s) in the memory to accomplish this. Processing continues to block1114.

In block 1114, the processor may generate one or more acknowledgementmessages and cause the transmitter to transmit the acknowledgementmessage(s) back to the device that sent the response message(s). Thesemessages indicate that the response sent by the remote device wassuccessfully received. In one embodiment, the SEND_SERIAL_NUM responsedescribed in Table 2, above, is transmitted. The ACK bit in field 512 isset, while no data fields 516 exist (or no data is inserted into asingle data field). Upon receipt of the acknowledgement message, aremote device may discontinue re-transmitting responses. Processing thencontinues back to block 1104, where another message is transmitted,requesting all remote devices to respond with their house code. Blocks1104 through 1114

Back in 1108, the if no response is received, this is an indication thatall remote devices within range of the message transmitted in block 1104have transmitted a response and that they have been successfullyreceived. In this case, processing proceeds to block 1110.

In block 1110 the processor selects a house code for self-assignment.Typically, the processor will select a house code from an availablenumber of house codes, while omitting any house code received in step1108 from consideration. The selected house code is then stored in thememory for use in subsequent transmissions, as shown in block 1116.

The methods or algorithms described in connection with the embodimentsdisclosed herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components.

Accordingly, an embodiment of the invention can include a computerreadable media embodying a code or processor-readable instructions toimplement the methods of operation of the master device and otherdevices in network 100 in accordance with the methods, processes,algorithms, steps and/or functions disclosed herein.

While the foregoing disclosure shows illustrative embodiments of theinvention, it should be noted that various changes and modificationscould be made herein without departing from the scope of the inventionas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the embodiments of the inventiondescribed herein need not be performed in any particular order.Furthermore, although elements of the invention may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

We claim:
 1. A method for detecting remote network devices in a network,comprising: transmitting a registration message by a network controldevice requesting a response from one or more remote network devices,the registration message comprising a first network identification codethat identifies a local network; determining by the network controldevice whether a response to the registration message is received withina predetermined wait-time period, the response transmitted by a firstremote network device in direct response to receiving the registrationmessage transmitted by the network control device and determining by thenetwork control device that the first network identification codematches a second network identification code stored within the remotenetwork device, the response comprising identification information ofthe remote network device; when the response is received within thepredetermined wait-time period, re-setting by the network control devicethe predetermined wait-time period; and when the response is notreceived within the predetermined wait-time period, terminating by thenetwork control device the method.
 2. The method of claim 1, furthercomprising: when the response is received within the predeterminedwait-time period, storing by the network control device theidentification information associated with the first remote networkdevice in a memory.
 3. The method of claim 1, further comprising: whenthe response is received within the predetermined wait-time period,transmitting by the network control device an acknowledgement to thefirst remote network device.
 4. An apparatus for detecting remotenetwork devices in a network, comprising: a memory for storingprocessor-executable instructions, a first network identification codethat identifies a local-area network, and identification information ofany detected remote network devices; a transmitter for transmittingregistration messages; a receiver for receiving responses from anyremote network devices; and a processor for executing theprocessor-executable instructions that causes the apparatus to: transmita first registration message requesting a response from one or more ofthe remote network devices, the registration message comprising a firstnetwork identification code; determine whether a response to theregistration message is received within a predetermined wait-timeperiod, the response transmitted by a first remote network device indirect response to receiving the registration message and determiningthat the first network identification code matches a second networkidentification code stored within the remote network device, theresponse comprising identification information of the remote networkdevice; when the response is received within the predetermined wait-timeperiod, re-set the predetermined wait-time period; and when the responseis not received within the predetermined wait-time period, stopdetermining whether the response is received.
 5. The apparatus of claim4, wherein the processor-executable instructions further compriseinstructions that cause the apparatus to: store the identificationinformation associated with the first remote network device in a memorywhen the response is received within the predetermined wait-time period.6. The apparatus of claim 4, wherein the processor-executableinstructions further comprise instructions that cause the apparatus to:transmit an acknowledgement to the first remote network device when theresponse is received within the predetermined wait-time period.
 7. Amethod, performed by a remote network device, comprising: receiving aregistration message from a network control device, the registrationmessage comprising a first network identification code, the networkidentification code for identifying a local network; and in directresponse to receiving the registration message from the network controldevice performing each of determining whether the first networkidentification code matches a second network identification code storedwithin a memory of the remote network device, determining whether theremote network device has previously responded to a previously-receivedregistration message, and transmitting a response to the registrationmessage when the second network identification code matches the firstnetwork identification code and when the remote network device has notpreviously responded to the previously-received registration message. 8.The method of claim 7, wherein determining whether the remote networkdevice has previously responded to a previously-received registrationmessage comprises determining whether an acknowledgement message hasbeen received prior to receipt of the registration message.
 9. Themethod of claim 7, further comprising: setting a flag in response totransmitting the response, the flag indicative of transmission of theresponse.
 10. The method of claim 9, wherein determining whether theremote network device has previously responded to a previously-receivedregistration message comprises determining whether the flag is set. 11.A remote network device, comprising: a memory for storingprocessor-executable instructions, a first network identification code,and identifying information of the remote network device; a receiver forreceiving a registration message, the registration message transmittedby a network control device, the registration message comprising asecond network identification code, the second network identificationcode for identifying a local network; and a transmitter for transmittinga response to the registration message; a processor for executing theprocessor-executable instructions that cause the remote network deviceto respond directly to receiving the registration message from thenetwork control device by performing each of comparing the secondnetwork identification code in the received registration method to thefirst network identification code, determining if the remote networkdevice has previously responded to the network control device, andtransmitting the response when the second network identification codematches the first network identification code and when the remotenetwork device has not previously responded to the network controldevice.
 12. The remote network device of claim 11, wherein theprocessor-executable instructions that cause the remote network deviceto determine if the remote network device has previously responded tothe network control device comprises instructions that cause the remotenetwork device to: determine whether an acknowledgement message from thenetwork control device has previously been received.
 13. The remotenetwork device of claim 11, further comprising instructions that causethe remote network device to: set a flag in response to transmitting theresponse, the flag indicative of transmission of the response.
 14. Theremote network device of claim 13, wherein the processor-executableinstructions that cause the remote network device to determine if theremote network device has previously responded to the network controldevice comprises instructions that cause the remote network device todetermining whether the flag is set.